Building information modeling (BIM) tools are frequently used by building designers to design the layout of the electrical and signal distribution systems of the building. Such systems include the power distribution system of the building, which in turn is comprised of devices (e.g. power outlets, light fixtures, ventilation fan motors, etc.), power supply panels, circuits between the devices and the panels, and the electrical pathway elements that carry the circuits (e.g. conduits, junction boxes, metal-clad (MC) cables, etc.). Such systems also include control and signal distribution systems, which again are comprised of devices (e.g. fire alarm sensors, security cameras, control actuators, etc.), distribution sources (e.g. control panels, patch panels), circuits between the devices and the sources, and pathway elements that carry the circuits. In using such a BIM tool, the modeler selects the locations of the various devices on the floor plan of the building, as well as the locations of the distribution sources that supply the devices with electrical power or signals. The modeler then assigns a circuit of one of the sources to each of the devices. Finally, the modeler selects the locations of a string of pathway elements between each device and its associated source that provides an electrical wiring pathway between the device and its assigned circuit. The BIM tool records the x-y-z locations of the devices and the distribution sources, the x-y-z locations of the strings of pathway elements, and the identity of the distribution source and circuit assigned to each device.